Cisco: Power (Over Ethernet) To The People

When it comes to enterprise networking, everyone loves Ethernet -- and they may adore it even more now that vendors are starting to roll out gear supporting the Power over Ethernet (PoE) standards, which allow the network to bring juice to connected devices. Following Cisco's announcement of new standards-based PoE wares, Networking Pipeline talked with Steven Shalita, Cisco senior manager for LAN switching worldwide product marketing, about the particulars of PoE.

Networking Pipeline: What are the infrastructure changes that need to be considered when installing PoE? Do users need to replace wiring?

Steven Shalita: For the most part, no. PoE is designed to work over the same cables, Cat 3 and Cat 5, that are in the walls today. The only changes are in the LAN switch chassis and the end devices, which need to be devices that support power over the net. The only other factor then is the power in the wall, which needs to deliver enough power to the switch to supply the devices.

Networking Pipeline: Do most current switches have enough extra power to supply connected devices?

Shalita: Typically, the normal switch does not have enough power. The wall outlet usually delivers enough just for the switch itself. It's a pretty complex problem to figure out how much power you need, so in the next couple of weeks, we're going to provide calculators with different classes of end devices, to help customers figure out how much power they need from the wall, or from UPS devices. We want to make PoE simple to deploy.Networking Pipeline: Isn't PoE all about powering IP phones, to make Ethernet voice as reliable as the circuit-switched voice networks?

Shalita: The most intuitive uses of PoE are IP phones and wireless access points. But the uses for PoE are much broader than that. There's the possibility of constructing a video surveillance network, where the cameras can be anywhere in a building, regardless of where the power is. That's important to government, education and business customers. PoE is a truly revolutionary step in networking, that enables a whole new way of thinking. It allows a whole new range of uses for the LAN infrastructure.